1080i vs 1080p

While I chastise about.com for over-simplifying things, they do have a number of great back to the basics type articles well suited for folks who are about to jump into the home theater arena. In today's article they explain the difference between 1080i and 1080p

From the article:

1080i and 1080p are both High Definition display formats for HDTVs.
1080i and 1080p signals actually contain the same information. Both
1080i and 1080p represent a 1920×1080 pixel resolution (1,920 pixels
across the screen by 1,080 pixels down the screen). The difference
between 1080i and 1080p is in the way the signal is sent from a source
component or displayed on an HDTV screen.